How do you write 18 as a product of prime factors?

Question

41177 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-09-22T20:29:37

#18 = 2xx3xx 3 #

We take 18 and break it down into factors until we reach numbers that are primes.

#18 :rarr 9 and 2#

#18 = 9 xx 2 #

#9# breaks down further into #3 and 3#

#9: rarr 3xx3 #

The prime factors are multiplied together to get a product at the end and together make the answer.

#18 = 2xx3xx3#

Answer 2 · 2018-01-18T08:47:05

See explanation.

To write a prime decomposition of a number #x# you follow this procedure:

Find the lowest prime number #p# which divides #x#. Write #x# as a product: #x=p*x_1#
Repeat this procedure until #x_1# is a prime number.
In the final step you can write the product(s) of repeating prime numbers as a power(s).

Here we have:

#x=18#

It is an even number, so we can write that: #18=2*9#

#9# is a compound number; it is divisible by a prime number #3#:

#18=2*3*3#

Now all the numbers are prime, so the decomposition is complete:

#18=233#

The product of 2 numbers #3# can be written as a power: #3*3=3^2#, so the final answer can be written as:

Answer 3 · 2018-01-20T01:18:18

#18=2xx3xx3#

Divide #18# by the prime number #2#.

#18-:color(red)2=9#

Divide #9# by the prime number #3#.

#9-:color(red)3=color(red)3#

This is as far as you can go.

#18=color(red)2xxcolor(red)3xxcolor(red)3#